1. Field of the Inventions
The present inventions relate to engines, and particularly to engines provided with a crankcase with which a main cylinder body can be integrally formed.
2. Description of the Related Art
Conventional motorcycle engines, as well as some other types of engines, include a piston disposed for reciprocating motion inside of a cylinder, and a crankshaft can be connected to the piston via a connecting rod. This allows the reciprocating motion of the piston to be converted into a rotational motion of the crankshaft.
Japanese Patent JP-A-Hei 4-075364 discloses such a well-known conventional motorcycle engine. This engine can be a V-type, 4-cylinder engine, provided with a crankcase on which a main cylinder body can be integrally formed. In this V-type, 4-cylinder engine, a crankcase can be divided into an upper and a lower crankcase and having a main cylinder body integrally formed on the upper crankcase. A cylinder head can be mounted to the top side of the main cylinder body on the crankcase and tilts forwardly to form a front bank. Another cylinder head can be mounted to the topside of the main cylinder body on the crankcase and tilts rearwardly to form a rear bank.
An intake and an exhaust camshaft are mounted in each cylinder head. A cam chain transmits a rotary motion of the crankshaft to the intake and exhaust camshafts. A chain guide member guides the loosened-side of the cam chain. Additionally, a cam chain tensioner can be used to maintain tension in the cam chain with the chain guide member.
The V-type, 4-cylinder engine disclosed in the JP-A-Hei 4-075364 has a chain chamber for accommodating the cam chain provided inside the cylinder head and the crankcase. A housing portion for housing a transmission can be integrally formed at the rear of the main cylinder body of the rear cylinder bank on the crankcase portion thereof.